Sitio web
An oceanic species, the Pink-footed Shearwater spends most of its time in the open ocean over the relatively shallow waters of the Eastern Pacific continental shelf. It is seldom seen from shore. To capture its prey (mainly small fishes, squid and crustaceans), the shearwater plunges into the water or dives from the surface while swimming. While underwater, the bird swims using its wings to propel itself. The Pink-footed Shearwater is known to follow fishing boats and feed on the bycatch.
The Pink-footed Shearwater has an extremely small breeding range restricted to several islands off the coast of Chile: Robinson Crusoe and Santa Clara in the Juan Fernandez Islands, and on Mocha Island off Arauco. It nests in colonies, with each breeding pair excavating a ground burrow four to six feet in length on grassy or forested slopes. In December or January, the female lays one white egg per clutch, and both parents incubate as well as feed the chick once it has hatched. During the non-breeding season, the seabird can be found in waters off western North America, primarily off Mexico’s Baja Peninsula, California, Washington, and British Columbia. The northern end of the species’ range shifts from year to year, in response to the variability in ocean temperatures caused by the El Niño Southern Oscillation. Although the bird ranges as far north as the Gulf of Alaska and the southern Bering Sea, west coast of British Columbia is thought to be the northern limit of where it regularly occurs.
Recent population estimates put the number of Pink-footed Shearwaters at approximately 60,000 birds, although the population is thought to be in decline for a variety of reasons. Due to its restricted breeding range, the global population of Pink-footed Shearwaters is inherently vulnerable. Introduced predators, such as cats, dogs, coatis, and rats, prey on both eggs and chicks. Uncontrolled grazing by introduced goats and rabbits has led to soil erosion, putting burrows at risk. Although now illegal, humans have been documented harvesting up to 20 percent of chicks annually at Mocha Island as recently as 1998. Entanglement in fishing gear while in pursuit of bait or bycatch can result in significant shearwater mortality. Oil spills, marine pollution, and ingestion of plastic debris remain constant threats. Food availability may also be an issue, especially due to human over-exploitation of some fish stocks targeted by shearwaters.
